Low resolution video stream here currently: http://tourofmissouritracker.com/
Universalsports is supposed to have higher resolution video for last 2 hours of race. The relay plane is not up until then.
CyclingNews has a live ticker at: http://live.cyclingnews.com/
Stage information from the official website:
Stage 1 – St. Louis, circuit race, 75 miles (120.7 km)
A new kickoff point for the third Tour of Missouri will be a showcase of St. Louis on Labor Day Weekend. While the terrain is relatively easy, the course is fast and technical, which will make things interesting from the start. Everyone will have fresh legs and a shot at the first yellow jersey of the tour, making this opening day an exciting one.